Five people have been killed and several others were “gravely injured” during a shooting Thursday afternoon in the newsroom of the Capital Gazette, according to Anne Arundel County Acting Police Chief William Krampf.

Krampf said during a press briefing Thursday evening that the shooter is in custody, but declined to offer any information about his identity, or the type of weapon used. The shooter was described as a “white male in his 20s” and several media outlets report that he used a shotgun during the attack.

While thousands of people offered their condolences on Twitter, Phil Davis, a Capital Gazette crime reporter who was in the building at the time of the shooting, offered some of the first information about the shooting in a series of tweets sent while he was waiting to be interviewed by police.

“Gunman shot through the glass door to the office and opened fire on multiple employees. Can’t say much more and don’t want to declare anyone dead, but it’s bad,” Davis wrote on Twitter as he waited to be interviewed by police. “There is nothing more terrifying than hearing multiple people get shot while you’re under your desk and then hear the gunman reload.”

A single shooter shot multiple people at my office, some of whom are dead.

In a subsequent interview, Davis told the Baltimore Sun (which owns the Gazette) that the shooting was like “a war zone” inside the newspaper’s offices, and that the situation would be “hard to describe for a while.”

“I’m a police reporter. I write about this stuff – not necessarily to this extent, but shootings and death – all the time,” he said. “But as much as I’m going to try to articulate how traumatizing it is to be hiding under your desk, you don’t know until you’re there and you feel helpless.”

Davis said he didn’t know why the shooter stopped firing, but that police arrived and quickly had him surrounded. Police said they responded to the scene within a minute. “If they were not there as quickly as they were it could have been a lot worse,” Annapolis Mayor Gavin Buckley said.

In response to the shooting, the New York Police Department said it would dispatch police to the offices of media organizations around the city.

While the total number of wounded isn’t yet known, Arminta Plater, a spokeswoman for a hospital near the newspaper, told the Associated Press that two patients had arrived there but she did not know their conditions.

The Anne Arundel County Police Department said that the shooting was reported at about 3:15 pm ET, when the department got the call about an “active shooter” at 888 Bestgate Road – the address of the paper’s offices. Agents from the ATF also responded to the scene.

President Donald Trump tweeted that his “thoughts and prayers are with the victims and their families” and thanked all of the first responders who were currently on the scene.

Prior to departing Wisconsin, I was briefed on the shooting at Capital Gazette in Annapolis, Maryland. My thoughts and prayers are with the victims and their families. Thank you to all of the First Responders who are currently on the scene.

Absolutely devastated to learn of this tragedy in Annapolis. I am in contact with County Executive Steve Schuh, and @MDSP is on the scene assisting @AACOPD. Please, heed all warnings and stay away from the area. Praying for those at the scene and for our community. https://t.co/bI6PdUjHfh

While police haven’t released a motive (or even a name), some people have begun to point fingers at pundit Milo Yiannapolous, who told The Observer“I can’t wait for the vigilante squads to start gunning journalists down on sight”

Yesterday, Milo Yiannapolous urged people to shoot and kill journalists. Today, multiple journalists at the Capital Gazette newspaper in #Annapolis were murdered.